Closure For A Container

ABSTRACT

A closure for a container having a circular opening defining an axis and a lip around said opening, the closure comprising: an inner component having a collar portion for locating about the exterior of the container beneath the lip of the container and a sealing portion which extends from said collar portion over an upper surface of said lip; and an outer component for fitting over the inner component and interacting therewith for releasably securing the collar portion under the lip, wherein the outer component has a skirt part for locating about the collar portion of the inner component, and the collar portion comprising a plurality of spaced apart radially moveable parts around its circumference pivotally joined at their lower ends by a ring extending around the entire circumference of the collar portion. The sealing portion may be formed of flexible material or may be formed of a relatively rigid material with a flexible sealing member, eg an o-ring, carried thereby.

TECHNICAL FIELD

This invention relates to a closure for a container, for example a container for housing a beverage or foodstuff. The invention is particularly concerned with closures for containers having a lip and an opening and preferably no thread features on the exterior of the container.

BACKGROUND ART

The applicant has proposed a number of different types of closures for containers examples of which are described in WO2006/000774, WO2007/091008 and WO2007/057659 and the disclosure thereof is incorporated herein. These known closures comprise a cap that fits over a collar which fits around the exterior of a container beneath the lip of the container and a one-piece plastic ‘crown’ cap. Whilst these are satisfactory in many cases, the present invention provides improvements which simplify the construction of the closure and/or of the container whilst maintaining or improving its performance.

SUMMARY OF INVENTION

According to a first aspect of the present invention, there is provided a closure for a container having a circular opening defining an axis and a lip around said opening, the closure comprising: an inner component having a collar portion for locating about the exterior of the container beneath the lip of the container and a sealing portion which, in use, extends from said collar portion over an upper surface of said lip; and an outer component for fitting over the inner component and interacting therewith for releasably securing the collar portion thereof under said lip wherein the outer component has a skirt part for locating about the collar portion of the inner component, the collar portion comprising a plurality of spaced apart radially moveable parts around its circumference pivotally joined at their lower ends by a structure extending around the entire circumference of the collar portion.

The first aspect is thus able to provide a cap-on-collar closure in which the collar is combined with a sealing component (and is preferably integrally formed therewith).

According to a second aspect of the present invention there is provided a closure for a container having an opening defining an axis and with an outwardly projecting lip around said opening, the closure comprising an inner member having an expandable/contractable portion for engaging an outer surface of said lip and an outer member for mounting over said inner member such that axial and/or rotational movement of the outer member relative to the inner member, when said inner member is fitted over said lip, is arranged to hold and/or press said expandable/contractable portion into secure engagement with the container beneath said lip, an inner surface of the inner member that contacts the container and/or the outer surface of the container being of a nature such as to provide a high friction engagement between the inner member and the container whereby relative rotation of the inner and outer members can be effected by a rotational force applied between the outer member and the container.

The second aspect is thus able to provide a cap-on-collar closure in which a high friction engagement between the collar and the container is provided in place of an ant-rotation feature.

The invention also relates to a container adapted to receive a closure as described in the first and/or second aspects of the invention and to such a closure when fitted to a container so as to close the container opening.

The invention also relates to a closure of the type described above when fitted to a container so as to close the container opening. Preferred or optional features of the invention will be apparent from the subsidiary claims and the following description.

Directional terms, such as upper and lower, as used herein are to be understood to refer to refer to directions relative to a container standing on a horizontal surface with the axis passing through its opening being substantially vertical (unless the context clearly requires otherwise).

One of the advantages of the invention is that it enables a closure to be provided which does not need the external surface of the container to have thread features and/or anti-rotation features. This enables a container to have a ‘lip-friendly’ form, eg a smooth exterior. Such a smooth exterior is also highly desired for aesthetic reasons and such a neck finish in combination with a high performance closure is sought after in the trade. In some embodiments, the invention also enables a closure to be provided which can be used with existing, standard containers or neck finishes so investment in tooling to manufacture a special form of neck finish can be avoided.

The container is typically formed of a plastics material, eg polyethylene terephthalate (PET), and formed by injection moulding followed by blow moulding, or may be formed of glass. Such containers are very well known.

The invention seeks to improve on known closures for bottles and for wide-mouth containers. A one-piece metal closure known as the ‘crown cap’ is well known for closing bottles, eg beer bottles. The invention seeks to provide a two-piece cap which can be used in place of the conventional crown cap. In addition, the invention seeks to provide a closure with a seal which is able to withstand the temperatures and pressures that arise when a beverage container, such as a beer bottle, is pasteurised. This is more challenging when a plastics closure is used rather than a metal one. In many cases, it is desirable for the closure to provide a hermetic seal, ie to seal the container from ingress or egress of gas, particularly the ingress of oxygen and the egress of carbon dioxide. Acceptable standards for such seals are well known in the food and beverage packaging industry to provide a satisfactory shelf-life for the product and to maintain the desired qualities of the product.

In some embodiments of the invention, a two-piece closure is provided for a wide-mouth container as a collar portion and sealing portion are provided as a single component. In other arrangements, a separate sealing member (such as an o-ring seal), may be carried by the sealing portion.

BRIEF DESCRIPTION OF DRAWINGS

The invention will now be further described, merely by way of example, with reference to the accompanying drawings in which:

FIGS. 1 and 2 are cross-sectional views of a first embodiment of a closure according to the invention when applied to a bottle neck, FIG. 1 shows the parts thereof located over the opening but prior to securement thereto and FIG. 2 shows the parts when the closure has been moved into secure engagement with the bottle neck;

FIGS. 3A and 3B show a side view and a cross-sectional view (taken on line E-E of FIG. 3A) of an inner component of the closure shown in FIGS. 1 and 2;

FIGS. 4A and 4B show perspective views from above and beneath of the inner component of FIG. 3;

FIGS. 5A and 5B show a side view and a view from beneath of an outer component of the closure shown in FIGS. 1 and 2;

FIGS. 6A and 6B show perspective views from above and beneath of the outer component of FIG. 5;

FIGS. 7 and 8 are cross-sectional views of a second embodiment of a closure according to the invention when applied to a container neck, FIG. 7 shows the parts thereof located over the opening but prior to securement thereto and FIG. 8 shows the parts when the closure has been moved into secure engagement with the container neck;

FIGS. 9A and 9B show a side view and a cross-sectional view (taken on line A-A of FIG. 9A) of an inner component of the closure shown in FIGS. 7 and 8;

FIGS. 10A and 10B show perspective views from above and beneath of the inner component of FIG. 9;

FIGS. 11A, 11B and 11C are plan, bottom and side views of a third embodiment of a closure according to the invention when applied to a container neck;

FIGS. 12A and 12B are perspective views from above and beneath of the closure shown in FIG. 11;

FIGS. 13A and 13B are side and perspective sectional views of the closure shown in FIG. 11 taken along line A-A and FIGS. 13C and 13D are side and perspective sectional views of the closure shown in FIG. 11 taken along line B-B;

FIGS. 14A, 14B and 14C are plan, bottom and side views of an inner component of the closure shown in FIGS. 11 to 13;

FIGS. 15A and 15B are perspective views from above and beneath of the inner component shown in FIG. 14;

FIGS. 16A and 16B are side and perspective sectional views of the inner component shown in FIG. 14;

FIGS. 17A, 17B and 17C are plan, bottom and side views of an outer component of the closure shown in FIGS. 11 to 13;

FIGS. 18A and 18B are perspective views from above and beneath of the outer component shown in FIG. 17;

FIGS. 19A and 19B are side and perspective sectional views of the outer component shown in FIG. 14;

FIGS. 20A shows a sectional view similar to those of FIGS. 13A and 13C but taken on a plane that shows a first type of stop feature that may be used in the third embodiment and FIG. 20B shows an enlarged, perspective view of part of FIG. 20A showing the stop feature; and

FIGS. 21A, 21B, 21C and 21D show a side view, sectional view, perspective view and sectioned, perspective view of another form of container that may be used with the third embodiment showing an alternative type of stop feature therein.

DESCRIPTION OF PREFERRED EMBODIMENTS

The closure shown in FIGS. 1-6 comprises an inner component having a collar portion for fitting about the exterior of a container 2, in this case a bottle neck having a container opening defining an axis A, and which has radially moveable parts 3 spaced around its circumference for engaging beneath a lip 2A of the container 2, and an outer component having a skirt part 4A for locating about the radially moveable parts 3 of the inner component.

In this embodiment, the outer component 4 is designed to be located over the inner component 1 by substantially axial movement therebetween and comprises one or more cam surfaces 4B on its inner surface which engage the upper ends of the radially moveable parts 3 as the components are moved axially together so as to progressively press the parts 3 inwards into tight frictional engagement with the exterior of the container beneath the lip 2A of the container 2. This camming action is due to the axial movement between the inner and outer components 1 and 4 and the further they are moved axially together, the greater the inward movement of the parts 3 until the parts 3 are moved into tight frictional engagement with the container (as shown in FIG. 2).

The inner component is by this means effectively secured against rotation relative to the container so that the outer component can be rotated relative to the inner component simply by applying a rotational force between the outer component and the container. This is of great importance as it means that high speed capping heads can be used to apply the closures to containers without the need to directly hold the inner component to prevent it rotating on the container (which would also be very difficult when the inner component does not project beyond the outer component) and without the need to provide an anti-rotation feature (such as one or more inter-engaging projections and recesses) between the inner component and the container (which spoil the smooth exterior of the container and prevent standard containers being used).

This is also important to the end user as they can remove and re-apply the closure simply by applying the required forces to the outer component of the closure whilst holding the container (or whilst the container is otherwise held still) without any need to interact with the inner component.

The cam surfaces 4B may be provided by an annular portion of the outer component at the point where its diameter changes as shown in FIGS. 1 and 2. The cam surfaces 4B are thus at the point where the cap transitions from a smaller diameter (upper) portion to a larger diameter (lower) portion.

Once the outer component 4 has been moved axially over the inner component 1 so as to press the radially moveable parts 3 inwards, it is twisted relative to the inner component 1 about the axis A so as to engage securement means which releasably secure the inner and outer components together in this position. In the embodiment shown, the securement means comprises substantially upwardly facing surfaces 5A of inward projections 5 at the lower end of the skirt part 4A of the outer component and substantially downwardly facing surfaces 3A of the radially moveable parts 3. The surfaces 5A and 3A may provide a bayonet-form of engagement between the inner and outer components and/or a thread-like engagement therebetween.

In order to releasably secure the inner and outer components 1, 4 together in this manner, a relatively small twist or rotation therebetween is required. At the most, this is 360 degrees or less, preferably 180 degrees or less, 90 degrees or less and most preferably 45 degrees or less (as will be described further below).

The bayonet or thread like engagement is preferably of the multi-start type. The inner and outer components may, for instance, be provided with eight sets of thread-like features around their circumference with four start points or nine sets of thread-like features and three start points. It will thus be appreciated that each thread path may thus extend over two or three adjacent thread-like features around the circumference of the inner component.

In the embodiment shown in FIGS. 1 and 2, the inner component 1 also comprises a flexible sealing portion 6 which extends over the opening in the bottle neck, over an upper surface of the container lip and extends down the exterior of the bottle neck. The flexible portion 6 is preferably integrally formed with the radially moveable parts, eg by a two-shot moulding process. The radially moveable parts are formed of a relatively rigid material, eg polyethylene terephthalate (PET), and the flexible portion of a relatively flexible material eg an elastomer. The function of the flexible sealing portion 6 will be described further below.

In the embodiment shown in FIGS. 1 and 2, the outer component 4 comprises a top part from which the skirt part depends and which extends across the upper surfaces of the lip 2A and across the container opening.

The inner component 1 will now be described in more detail with reference to FIGS. 3A and 3B.

As shown in these figures, the inner component comprises two principal parts: a collar portion which comprises a ring 3B with a plurality of radially moveable parts 3 upstanding from the ring 3B and circumferentially spaced around the ring 3B and a flexible sealing portion (described further below). Each of the moveable parts 3 has a rounded upper end 3C for engagement with the cam surfaces 4B described above and for engaging the underside of the container lip 2A. Preferably, the upper end 3A of the moveable parts 3 is shaped to substantially match the concave profile of the container on the underside of the lip 2A (as shown in FIG. 2).

The outer face 3D of each of the moveable parts is substantially flat so as to be a snug fit within the skirt 4A of the outer component 4 when the closure is in an unsecured position (as shown in FIG. 1). Each moveable part 3 also has a lower, substantially downwardly facing surface 3A as described above. This acts to retain the inner component 1 within the outer component 4 in the unsecured position (as shown in FIG. 1) so the inner and outer components can be easily pre-assembled; the inner component 1 being a snap fit within the outer component 4 as they are brought together in the axial direction, the moveable parts 3 flexing as they pass over the inward projections 5 until they snap outwards so the lower surface 3A of the moveable part engages the upper surface 5A of the inward projections 5.

In the position shown in FIG. 1, the surfaces 3A and 5A are substantially horizontal ie perpendicular to axis A. However when the inner and outer components are moved axially relative to each other to the position shown in FIG. 2, the moveable parts 3 are flexed inward. The lower surface 3A of the moveable part is thus tilted inwards so as to be inclined to the horizontal. Accordingly, the upper surfaces 5A are preferably shaped so that when the outer component 4 is twisted to the secured position the surface 5A is similarly inclined to the surface 3A.

In addition, in many cases, is desirable for the engagement between the surfaces 3A and 5A, as the outer component 4 is rotated or twisted about axis A to a second position, for the inner and outer component to be drawn together axially whereby the outer component 4 is drawn down towards the upper surface of the container lip 2A and the moveable parts 3 drawn tightly upwards beneath the lip 2A of the container. The surfaces 3A, 5A are thus inclined in the circumferential direction in the manner of a screw thread to effect a tight securement of the closure to the container as the inner and outer components rotated relative to each other in a tightening or closing direction about axis A. As the outer component is rotated relative to the inner component, the outer component is drawn down so as to compress the flexible sealing portion of the inner component against the upper surface of the container lip and the moveable members 3 are pressed upwardly into secure engagement with the container beneath the container lip.

The ring 3B can be relatively slim in cross-section (compared to the moveable parts 3) and serves to maintain the circumferential spacing of the moveable parts 3. It also provides a pivot point about which the moveable parts 3 can flex in the radial direction. The parts 3 may also be pivotally joined at their lower ends by other structure that extends around the entire circumference of the component (in place of the ring).

In the embodiment shown, the ring 3B projects beneath the skirt 4A of the outer component so is visible from the exterior (as shown in FIGS. 1 and 2). However, in other embodiments, the ring may be concealed by the skirt, at least when in a secured position corresponding to that shown in FIG. 2.

An important feature of the collar portion of the inner component is that the upper ends of the moveable components that are free to flex radially inwards and outwards, this movement taking place about a pivot at or towards the lower end of the collar (in contrast to a collar which is located the other way up ie with the moveable parts extending downwards from a ring portion).

The function of the collar portion is somewhat similar to that of a collet chuck; the cam surfaces engage the arms of the collar and press them inwards and further axial movement therebetween moves the arms further inwards until they are tightly wedged against the exterior of the container (under the container lip) and the frictional engagement therebetween is sufficient to prevent the collar rotating about the container when rotational forces are applied between the closure and the container (to tighten and release the closure). The collar portion thus grips the container neck and effectively becomes part thereof as if the container neck itself was provided with the securement features carried by the collar by means of which the closure is secured to the container.

The other principal part of the inner component is the flexible sealing portion 6. In the embodiment shown, this is in the form of a cap with an upper end 6A extending across the upper end of the container 2 and an upper surface of the lip and a skirt portion extending down the outside of the bottle neck to the ring 3B of the collar.

The flexible portion 6 performs several functions. First, it acts as a sealing component in that it is sandwiched between the outer component 4 and the upper surface of the lip 2A of the container so as to provide a gasket seal therebetween. In the arrangement shown, it also extends across the mouth of the container and so closes the container opening. In addition, the flexible portion lies between the substantially rigid moveable parts 3 and the outer surfaces of the bottle neck and so acts as a high friction component between these surfaces. In other arrangements (not shown), the sealing portion extends over the lip of the container but does not extend across the mouth of the container so does not close the container opening.

Thus, when the outer component is rotated relative to the inner component, the frictional engagement between the inner component and the container is greater than that between the inner and outer components.

The inner component is thus inhibited from rotating relative to the container without the need to provide anti-rotating features (which can spoil the outer appearance of the container) and without the need to extend the inner component beyond the outer component to the extent it can be gripped (to prevent rotation) by a user's hand.

It will be appreciated that the flexible nature of the flexible component, enables it to be flexed by the moveable parts as they are pressed inwards between the positions shown in FIGS. 1 and 2. Furthermore, when the closure is to be removed, the flexible nature of the flexible component assists in urging the moveable parts 3 back to their original outward positions.

As indicated above, the collar portion and the flexible sealing portion are preferably integrally formed. This can be achieved, for example, by a two-shot moulding technique in which the different materials are consecutively injected so they are integrally bonded or connected to each other. This also has the significant advantage that the closure comprises just two parts: the inner component and the outer component. In known cap-on-collar closures, it is usually necessary for the sealing component to be provided separately or secured in some manner to the underside of the outer component.

The outer component 4 will now be described in more detail with reference to FIGS. 5A and B and FIGS. 6A and B.

In the embodiment shown, the outer component is in the form of a cap with an upper portion 4C which extends over the upper surface of the lip 2A and extends across the opening of the container 2 and has a skirt portion 4A depending therefrom.

The skirt portion 4A is provided with inwardly extending projections 5 at or toward the lower end thereof. As described above, the upper surface 5A of each projection 5 is preferably inclined circumferentially so it acts as a screw thread and tilts radially inwards to an increasing extent along its circumferential length so as to match the inclination of the lower surface 3A of the moveable part 3 that it engages. This thread path may extend over two or three adjacent parts 3.

Also, as mentioned above, the closure is designed so that only a relatively small twist is required to move it from an unsecured (FIG. 1) position to a secured (FIG. 2) position. In the embodiment shown, a twist of only approximately 60 degrees is required. Accordingly, the inward projection 5 comprises six sections around the inner circumference of the skirt portion 4A as shown in FIGS. 5B and 6B.

As indicated above, the outer component engages downwardly fading surfaces of the radially moveable parts so as to secure and/or tighten the inner and outer components together in the axial direction. This is an important feature as it enables both the inner and outer components to be relatively short in the axial direction so they can be formed to resemble a conventional cap-like closure. This also means that the threaded engagement between the inner and outer components comprises circumferentially spaced apart features (the surfaces 3A of the respective parts 3). This enables the threaded engagement therebetween to require only a relatively small rotation or twist (rather than several complete rotations as required by a continuous helical thread form). Furthermore, this provides a very compact and robust construction. The upwardly facing surfaces 5A of the outer component apply an upward force which is directly transmitted via surfaces 3A through parts 3 which have a rigid, strut-like form to the underside of the lip 2A.

The provision of a high friction contact between the inner component and the container is also an important feature. As described, this is facilitated by providing a high friction flexible component between the moveable parts 3 and the outer surface of the container. It is also enhanced by providing a large surface area of contact between these components which is due, at least in part, to the radially inner surfaces of the moveable parts 3 having a shape which matches that of the external surfaces of the container. The sealing surface may, for example, extend over an outer surface of the lip, the underside of the lip and/or the outer surface of the container beneath the lip.

This high friction engagement can also be provided in other ways. The collar component may be provided with a lining of high friction material (irrespective of whether this is connected to a sealing component that passes over the upper surface of the container lip) or the inner surface of the collar component could be provided with a roughened finish which is sufficient to increase the frictional engagement with the container to the required level. In another alternative, a high friction sleeve, eg of rubber, could be fitted around the container neck or the container neck provided with a high friction finish.

In addition, the flexible sealing component extends over the upper surface of the lip 2A and so provides a sealing member between the closure and the container. The provision of a single component that acts both as a collar for fitting around the exterior of the container and as a sealing component between the closure and the container, is also a significant feature of this embodiment of the invention.

As described, when the outer component is moved with respect to the inner component so as to press the moveable parts 3 inwards, this movement is primarily axial. In other embodiments, this axial movement may be provided by means of a small twisting movement although it is the axial component that moves the cams downwards so as to press the parts 3 inwards. The twisting movement is preferably less than 360 degrees and more preferably less than 90 degrees or less than 60 degrees. This is in contrast to arrangements in which a small axial movement is a consequence of several complete rotations of the outer component relative to the inner component, eg as provided by a continuous helical thread path.

In some cases, movement of the cams relative to the radially moveable parts, deflects the moveable parts from an outer position to an inner position and holds the parts in the inner position in contact with the container body. In other cases, the movement of the cams serves to deflect the parts only a very small distance (eg if they are already in a generally inward position) and to press the parts firmly into contact with the container body and to hold them in contact therewith, eg to increase the frictional engagement between the inner component and the container. In other cases, the movement of the cams does not cause any appreciable deflection of the parts but acts merely to press the parts firmly into contact with the container body and hold them in this position. It should also be noted that even in such cases, manufacturing tolerances and/or creep of the plastics material over time may cause the parts to adopt a slightly more outward position than intended whereby the action of the cams will ensure they are pressed firmly into contact with the container body and held in this position. Reference herein to the parts being ‘pressed’ into engagement with the container is to be understood to cover all these possibilities. FIGS. 7-10 illustrate a second embodiment of a closure according to the invention. This is similar to that shown in FIGS. 1-6 but modified for use with a container, such as a wide-mouth container, in which the outer wall of the container is generally vertical (or only slightly outwardly tapering) beneath the container lip (as opposed to a bottle neck having a divergent, frusto-conical surface beneath the lip as shown in FIGS. 1 and 2). Parts corresponding to those of the embodiment shown in FIGS. 1-6 are given the same reference number but with the addition of a′.

FIGS. 7 and 8 indicate that the diameter of the container opening can be relatively wide (eg for wide-mouth containers as described in WO2006/000774 and WO2007/091008), typically 50 mm or greater, or relatively narrow, such as a conventional 28 mm bottle neck. For convenience, FIGS. 9 and 10 show the inner component 1′ being of a diameter for use with a bottle neck (as in FIGS. 1-6) although it would be of larger diameter if used with a wide-mouth container.

The inner and outer components 1′, 4′ of the closure shown in FIGS. 7-10 are very similar to those of FIGS. 1-6. The outer component 4′ is essentially identical and the ring 3B′ of the inner component is slightly shorter so that it does not project beyond the skirt 4A′ of the outer component 4′ when in the secured position (as shown in FIG. 8). The upper end 3C′ of the radially moveable parts 3 is also shaped so as to optimise the engagement with the under side of the container lip 2A′.

The closure shown in FIG. 7-10 operates in a very similar manner to that described above in relation to FIG. 1-6 although, in view of the different shape of the container neck, the moveable parts 3′ do not fit as snugly against the external wall of the container 2′ when in the inward position shown in FIG. 8.

In both cases, removal of the closure from the container is effected by rotation of the outer component in the loosening direction so as it no longer presses or holds the radially moveable parts of the collar portion beneath the container lip (this release may be due to axial and/or rotational movement of the outer component relative to the inner component). The radially moveable parts move outwards by virtue of their own resilience and/or by the resilience of the sealing portion to a position in which they no longer prevent vertical movement of the inner component due to engagement with the underside of the container lip. In some arrangements, the radially moveable parts may also be driven outwards by engagement with some other part of the outer component as it is rotated in the loosening direction.

The closure is then free to be moved vertically so as to open the container. This can be effected by pulling the closure vertically, which movement will be assisted if the pressure within the container is elevated, eg if it contain a carbonated beverage. In other arrangements (not shown), further rotation of the closure in the loosening direction assists in detaching it from the container.

In all cases, it is preferred for the inner and outer components to be removed together. In the illustrated embodiments, this is effected by the engagement of the projections 3 and 5 on the respective components as described above. Upward movement of the outer component thus results in upward movement of the inner component as well (once the radially moveable parts are no longer engaged beneath the lip of the container).

In further embodiments, in particular closures for widemouth containers, the inner and/or outer component may comprise a bore feature which projects though the mouth of the container into the interior thereof.

The bore feature preferably comprises a relatively rigid component, eg formed of PET or metal, and it may be integrally formed with the outer component or secured thereto. In a particularly advantageous arrangement, the outer component is able to rotate about the axis A relative to the bore feature. The outer component can this be rotated, eg to fasten or release the closure whilst the bore feature moves axially within the bore without rotating therein.

The bore feature may also be provided with an o-ring seal which engages and seals with the interior of the container (or an upper surface of the container lip). A bore feature is disclosed in co-pending UK patent application No GB1009429.0 and the disclosure thereof is incorporated herein. This describes an o-ring in the form of a toroid of an elastomer located in a groove or gland on the outer surface of a bore feature. It also describes an o-ring which is part of a resilient member moulded to fit the underside of the bore feature. The resilient sealing portion described above may include such a member. Thus, if the outer member shown in FIG. 2 projects into the bore of the container (rather than being flat) and the resilient sealing portion follows the underside of this feature (again, rather than being flat) the resilient component may be formed with a portion which simulates the function of an o-ring to provide a seal with the interior of the container. It will be appreciated that in cases in which the o-ring is a separate member, whilst it forms part of the component on which it is provided, it does comprise a third component of the closure.

It should be noted that in embodiments employing an o-ring seal as described above, the seal provided by the sandwiching of the flexible part of the inner component between the outer component and the upper surface of the container lip may no longer be required. In this case, the outer component need not engage and/or compress the flexible sealing component against the upper surface of the lip.

FIGS. 11-19 illustrate a third embodiment of a closure according to the invention. This also comprises an inner component 11 (see FIGS. 14-16) and an outer component 14 (see FIGS. 17-19) for fitting to the neck of a container 12 (see FIGS. 11-13). The inner component 11 comprises a collar portion similar to that of the first and second embodiments having a plurality of circumferentially spaced apart radially moveable parts 13 upstanding from a ring 13B and a sealing portion which extends from the collar portion over a lip 12A of the container (as best shown in FIG. 13).

The sealing portion comprises a bore feature 17 which, as mentioned in the further embodiments referred to above, carries an o-ring seal 18. The bore feature 17 may be formed of a relatively rigid material, eg a plastics material such as PET, and is preferably integrally formed with the collar portion and connected thereto by a plurality of connecting parts 17A which extend from the bore feature 17 over the lip 12A of the container 12 and down between the radially moveable parts 13 to the ring 13B.

In this embodiment, the inner component 11 is again designed so that, once fitted within the outer component 14, it does not project beyond the skirt of the outer component 14 so is effectively concealed thereby (as shown in FIGS. 11 and 12).

In the preferred arrangement of this embodiment, and as shown, the radially moveable parts 13 are moulded such that, in their unstressed state, they lie at a diameter smaller than the outer diameter of the lip 12A of the container. The inner component 14 is thus a snap-fit over the lip 12A of the container; when it is fitted axially thereto, the radially moveable parts 13 flexing outwards to permit the collar portion to be fitted over the lip 12A and then snap back inwards beneath the lip 12A so the inner component 11 is retained (at least to some degree) on the container 2 by the engagement of the radially moveable parts 13 (or at least some of them) beneath the lip 12A. As in the earlier embodiments, a first set of cam surfaces is provided on the outer component to interact with the radially moveable parts so as to press and/or hold them in a radially inward position when the closure is in the secured position.

As will be described further below, when the closure is to be removed from the container 12, these radially moveable parts 13 are driven outwards by engagement of upstanding tabs 13C thereon with a second set of camming surfaces 15D on the outer component 14 as the outer component 14 is rotated in a loosening direction relative to the inner component 11.

As shown in FIGS. 11A and 12A, the outer component 14 has a plurality of slots 14A around its upper periphery. In the arrangement shown, these are not functional features of the closure but are provided merely to facilitate the fabrication of other features of the outer component 14. They provide access for ‘core throughs’ used in the moulding process to form features on the inner surface of the skirt of the outer component 4. They may be omitted if other ways of fabricating the outer component 14 are used. However, in other arrangements they may provide at least part of the second set of camming surfaces referred to above and/or may be used to provide a visual indication of the state of the closure, eg as a tamper proof indication.

The sectional views shown in FIGS. 13A and 13B are taken through connecting parts 17A of the inner component 11 and illustrate how these connect the ring 13B to the bore feature 17 and the o-ring seal 18 carried by the bore feature 17. The sectional views shown in FIGS. 13C and 13D are taken through the radially moveable parts 13 and illustrate how these engage beneath the lip 12A of the container.

These views also show the o-ring seal 18 engaging an internal surface of the container 12. In the arrangement shown, this surface lies just beneath the opening and is parallel sided.

The inner component 11 will now be described in more detail with reference to FIGS. 14 to 16 (from which the o-ring has been omitted for clarity). The inner component 11 comprises a collar portion which comprises the ring 13B and the upstanding radially moveable arms 13 and a sealing portion which comprises the bore feature 12 (with o-ring 18) and which extends over the lip 12A of the container and is connected to the ring 13B of the collar portion by connecting parts 17A. The radially moveable arms 13 are spaced apart around the circumference of the collar portion and extend upwardly from the ring 13B. The outer surface of the radially moveable parts 13 is shaped to interact with features on the inner surface of the outer component 11 as will be described below and the tabs 13C extends from the upper, distal end of the radially movable parts 13 for engaging the second set of cam surfaces of the outer component 14 as described above.

As indicated above, the radially moveable parts 13 are biased so as to adopt a radially inward position such that they snap fit beneath the lip 12A of the container. They may be designed to snugly engage the outer surface of the container 12 or they may be designed to be a slightly looser fit (so they can be pressed more tightly into engagement with the container 12. However, some variation in their radial position is typical due to manufacturing tolerances and creep of the plastic material over time. Thus, in use, the radial moveable parts and pressed and/or held in the inner position by the interaction with the first set of cam surfaces of the outer component.

The lower end 13D of the ring 13B is preferably inclined so that it flares outwards so that the inner component 11 is a snap fit with the outer component 14 as they are brought together axially; the outer component 14 being provided with one or more inward projections 14B on the skirt thereof which snap over the flared ring 13B as the components are fitted together. This helps prevent the inner and outer components 11, 14 from disengaging with each other but permits limited axial movement therebetween once assembled.

In the first and second embodiments, the snap-fit between the inner and outer components was provided by inter-engagement of features which also provided the threaded connection between the inner and outer components. In this embodiment, the snap-in features 13B, 14B are separate from the thread features (which are described further below).

The connecting parts 17A are curved at their upper ends where they pass over a curved portion of the lip 12A of the container and are joined by an annular ring 17B that sits on a radially inner edge of the upper surface of the container lip 12A with the bore feature 17 extending downwards from this annular ring 17B.

The outer surface of the bore feature 17 is shaped to provide a gland 17C for locating the o-ring 18. In the arrangement shown (which is suitable for use with a container for holding still or carbonated drinks), the gland 17C comprise an upper surface 17D and a rear surface 17E and a small lower lip to help retain the o-ring in place. The spacing between the rear surface 17E of the gland and the inner surface of the container 12 is designed such that the o-ring 18 is slightly compressed (or, more accurately, deformed) when the inner component 11 is fitted to the container 12 and the bore feature located therein (as shown in FIG. 13).

Further details of sealing arrangements using an o-ring are provided in co-pending application PCT/GB2011/000846 and in the Dichtomatik O-Ring Handbook, published by Dichtomatik North America and referred to therein.

As in the above specification, the term ‘o-ring’ is to be understood to include a toroid of elastomer material having a circular cross-section (or other cross-sections) and other forms of seal which simulate the function of an o-ring.

The bore feature 17 preferably has a convex shape (when viewed from beneath) so as to reduce the ‘head space’ above a beverage held in the container 12. The convex shape also provides additional strength for resisting upward forces due to elevated pressures within the container 12. Rather than causing bowing of the bore feature 17 (which might occur if it had a flat shape), the majority of the upward force is transmitted via the connecting parts 17A and the ring 13C to the collar portion so as to locate the arms 13 more tightly under the lip 12A of the container. This arrangement is thus particularly advantageous for use with carbonated beverages.

FIGS. 17 to 19 provide more detailed views of the outer component 14. This is in the form of a cap with a substantially flat upper part 14C and a skirt portion 14D depending from the perimeter thereof. As mentioned above, a plurality of slots 14A are provided around the periphery of the upper part 14C to assist in fabrication of the component by permitting parts of the mould to pass through the upper part 14C in the formation of features (eg the second set of cam surfaces) on the interior of the component.

The internal surface of the skirt portion 14D is provided with features around the circumference thereof. As described above, a plurality of spaced apart projections 14A are provided adjacent the distal end of the skirt portion 14D so the inner component 11 can be snapped into the outer component 14 when they are moved together axially. A continuous circular projection could be provide but a series of shorter projections 14A gives the skirt 14D more flexibility so that it can flex as required to snap fit over the flared ring 14A of the inner component 11. It will be appreciated that a wide range of other features may be used to provide a similar snap-fit engagement between the inner and outer components 11, 14.

A number of features are also provided on the inner surface of the skirt portion 14D for interacting with the radially moveable parts 13 of the collar portion:

i) Deep pockets 15A are provided for accommodating each of the radially moveable parts 13 when they are driven outwards to disengage from the lip 12A of the container and the inner component removed from the container 12.

ii) A first set of cam surfaces 15B is provided for engaging the outer surfaces of the radially moveable parts 13 and pressing and/or holding them in the innermost position with a ramp 15C leading up to each of the cam surfaces 15B.

iii) A second set of cam surfaces 15D is provided for engaging the tabs 13C of the radially moveable parts 13 so these are driven radially outwards as the outer component 14 is rotated in a loosening direction relative to the inner component 11.

iv) Thread features 15E are provided for interacting with downwardly facing surfaces 13E (see FIGS. 14 and 15) of the radially moveable parts so that, once the inner and outer components 11, 14 have been engaged axially, rotation in a tightening direction engages them together, eg by means of a bayonet thread. Preferably, one or more of the thread parts of the inner and/or outer components 11, 14 are inclined so that rotation of the outer component 14 relative to the inner component 11 in the tightening direction moves them further together axially so that the outer component 14 is drawn down towards the lip 12A of the container and/or the inner component drawn 14 upwards under the lip 12A of the container.

A plurality of circumferentially spaced apart thread features of the type described provide a multi-start thread so that rotation of the outer component 14 relative to the inner component 11 through approximately 45 degrees (if eight sets of features are provide around the circumference) is sufficient to move the closure from an installation/removal position to a secure, tightened position (and vice versa). Other numbers of feature and other arrangements may be used to achieve a similar effect, preferably requiring relative rotation of 180 degrees or less and preferably 90 degrees or less.

The closure described above can be fitted to a container in a variety of ways. One particularly advantageous way is to first fit the inner component 11 to the container prior to assembly of the inner and outer components together. The inner component 11 is a snap-fit over the lip 12A of the container at the bore feature 17 closes the mouth of the container 12 with the o-ring 18 providing a seal between the inner component 11 and the container 12.

The inner component 11 may thus be fitted to the container 12 after the container 12 has been filled and provides a temporary closure of the container 12. The outer surfaces of the inner component 11 and the container 12 can thus be washed, eg to remove remnants of the contents they may have spilled or splashed whilst the container 12 was being charged, and then dried prior to fitting of the outer component 14 over the inner component 11. This is particularly advantageous in an automatic filling line, eg in which the containers are filled with a beverage such as beer, where it is desirable to ensure that the interaction between the features of the inner and out components, such as the thread features thereof, is not impeded by product residue.

The outer component 14 is fitted to the inner component 11 by moving them together axially so the flared ring 13D of the inner component 11 snaps past the projection 14B on the skirt portion of the outer component 14. The radially movable arms 13 are preferably aligned with the deep pockets 15A of the outer component as they are engaged. Rotation of the outer component 14 relative to the inner component 11, then brings the first set of cam surfaces 15B into engagement with the radially movable arms so as to press them into and/or hold them in engagement with the underside of the container lip 12A. The inner component is thus secured to the container as the arms 13 are held in engagement with the underside of the lip and are unable to move radially outwards so as to disengage therefrom.

To release the closure from the container, the outer component is rotated in the loosening direction so that the second set of cam surfaces 15D are brought into engagement with respective tabs 13C to drive them outwards. At the same time, the first set of cam surfaces move out of engagement with the radially movable arms and the deep pockets align therewith so the arms are able to be flexed outwards. The arms are thus disengaged from the underside of the lip. The user can then pull the closure axially upwards to withdraw the bore component (and the o-ring) from the container. The inner and outer components 11, 14 are thus removed as one component, the projection 14B of the outer component 14 engaging the underside of the flared parts 13D of the inner component so an upward force applied to the outer component applies an upward force to the inner component.

The second set of cam surfaces are outwardly facing surfaces of features provided in the outer component. As the outer component is rotated in the loosening direction, the tabs 13B of the radially moveable arms 13 engage these features and the cam surfaces 15D thereof drive the arms 15 outwards so they are disengaged from the underside of the container lip 12A. This provides a positive, reliable disengagement of the arms 13 from the lip 12A and reduces any chance of any of the arms catching on the lip as the closure is removed from the container.

It is found that when the container contains a carbonated beverage (or the internal pressure of the container is otherwise elevated relative to the environment outside the container), the internal pressure assists in raising the inner compartment 11, and hence the outer compartment 14, so very little (if any) upward force needs to be applied to remove the closure. Instead, it tends to open with a ‘pop’ as the o-ring disengages from the interior of the container. In such circumstances, the closure can thus be designed so that a raised internal pressure within the container provides a substantial proportion of the upward force required to remove the closure. It will also be appreciated that venting of the container is achieved as the o-ring disengages from the container. At least for a wide-mouth container, this provides an effective way of venting the container upon opening so no other venting mechanism is required.

To facilitate the above operation, it is necessary to rotate the outer component relative to the inner component. In the embodiment shown, this is achieved by providing the inner component and the container with one or more mutually engageable stop features which limit the relative rotation therebetween. The stop feature on the container may comprise one or more projections, ribs, indents or grooves in or beneath the lip of the container and the stop features on the inner component may comprise features on one or more of the radially parts or the connecting parts for engaging with the stop features on the container.

FIGS. 20A and 20B illustrate one form of stop feature. This comprises a semi-circular rib 19 projecting from the underside of the container lip 12A. As shown in FIG. 20B, this projects into one of the spaces between a radially moveable arm 13 and one of the connecting parts 17A so rotation of the inner component 11 relative to the container 12 is limited by engagement between the rib 19 and a side of either the radially moveable arm 13 or the connecting part 17A (depending which way the inner component 11 is rotated). Two ribs 19 at 180 degrees from each other are preferably provided.

It is desirable for the stop features 19 to limit rotation of the inner component 11 relative to the container 12 until the radially moveable arms 13 have been driven outwards far enough to disengage from the underside of the lip 12A. The rib 19 is thus designed to project far enough out from the lip 12A to achieve this.

FIGS. 21A-21D illustrate an alternative form of stop feature on the container 12. In this case, the stop feature comprises one or more substantially vertical grooves 20 through the lip 12A. The sections shown in FIGS. 21B and 21D are taken through two such grooves positioned at 180 degrees to each other. The inner component 11 is provided with one or more ribs (not shown) for engaging with these grooves 20. These ribs may be provided on the inner side of one or more of the radially moveable arms 13 or connecting parts 17A. In the latter case, it will be appredated that these ribs will need to be aligned with the grooves 20 when the inner component 11 is fitted onto the container 12.

Many other forms of stop features may be used comprising male and/or female features on the container and the inner component. Preferably the stop feature on the container in provided in or on the container lip. It is preferably provided in or on the outer side of the lip (as in FIGS. 20 and 21) but could also be provided on an upper or inner side of the lip 12A. In some cases, the stop feature may also be provided on the wall of the container at a short distance beneath the lip 12A. Preferably, the stop features is provided in the portion of the container that it formed by injection moulding, ie the lip 12A or part of the container wall a short distance below the lip 12A as its form can then be accurately determined (as opposed to being provided in part of the container 12 formed by blow moulding which tends to be less precise). The blow moulded part of the container can then be made any shape as it is not involved in the securement of the closure to the container.

By this means, the required rotation of the outer component relative to the inner component can be achieved by applying a rotational force between the outer component and the container. This is clearly particularly important when the inner component is recessed within the outer component so cannot be easily accessed by the user.

In an alternative arrangement, if it is desired to avoid any such features on the lip of the container, a high friction engagement may be provided between the inner component and the container as described above in relation to the other embodiments, eg by the provision of high friction surfaces on the inner component and/or the container.

In other circumstances, the inner and outer components may be pre-assembled by snap-fitting the inner component into the outer component prior container. This assembly can then be fitted to the mouth of the container by pressing the closure axially onto the container so that collar portion of the inner component fits over the lip (and preferably snaps into engagement with the underside of the lip) and the bore feature (and the o-ring seal carried thereby) are pressed into the interior of the container. The outer component is then rotated in the tightening direction to bring the first set of cam features into engagement with the radially moveable arms as described above.

When the inner and outer components are rotated relative to each other they preferably move between three positions: a closed position in which the first set of cams engage the radially moveable arms and hold these in an inner positions, an open position in which the second set of cams urge the radially moveable parts outwards and a neutral position between the open and closed positions in which the radially moveable arms are neither held or pressed in a radially inward position nor urged to a radially outer position.

When the inner and outer components are initially assembled with each other, they are preferably in the neutral position (although they can be assembled in any relative rotational position with respect to each other). It is also desirable for the inner and outer components to be releasably held in the open position. This can be achieved by providing one or more small projections (not shown) on the inner surface of the outer component which one or more of the tabs 13C has to bump over in order to engage the second set of cam surfaces 15D with the tabs 13C, These projections then provide resistance to the tabs 13C slipping back to the neutral position once they have been driven outwards by the second cam surfaces 15D but can be easily overcome by manually rotating the outer component towards the neutral position.

The embodiments illustrated in FIGS. 1 to 19 all have an inner component comprising sealing portion and a collar portion. As described, the sealing portion is involved in proving a seal against the container. In some cases, the sealing portion is formed of a relatively flexible material which, in use, is sandwiched between the outer component and the container so as to provide the sealing function (eg as shown in FIGS. 1 to 10). In other cases, the sealing portion is formed of a relatively rigid material, eg plastics material similar to that of the collar portion, and carries a flexible sealing portion, eg an o-ring, which provides a seal with the container (eg as shown in FIGS. 11-19). In both cases, the sealing portion may also extend across the opening and thus close the moth of the container (as shown in the drawings). However, in other embodiments, the sealing portion extends over the lip of the container but not across the mouth of the container. In these cases, the outer component is in the form of a cap which extends across the mouth of the container to close the container.

In the illustrated embodiments, the outer component is in the form of a cap which extends across the mouth of the container so as to close the container (whether or not is also closed by the sealing portion of the inner component). The cap may have a simple flat upper portion and/or may comprise a bore feature which extends into (and closes) the container. However, in other embodiments, it may have an annular form with an upper part lying above the lip of the container (and a skirt portion depending therefrom) but does not extend across the mouth of the container to close the container. Obviously, in this case, it is essential for the sealing portion of the inner component to extend across and close the mouth of the container.

Various modifications of the embodiment described with reference to FIGS. 11 to 19 are possible. In some arrangements, particularly for containers housing still beverages or containers with a relatively narrow opening (eg with a diameter of 28 mm or less), the seal can be arranged so that it seals against an upper surface of the container lip or against an edge of the lip where this meets the internal surface of the container. In such an arrangement, the bore feature may be omitted and may, for example, be replaced by a substantially flat portion extending across and closing the mouth of the container or an opening (in this case, the area labelled 17 in FIGS. 15A and 15B would either be a flat portion or an aperture). The seal may be an o-ring or other form of compression seal.

It will be appreciated that in all the embodiments shown in the drawings, the radially moveable parts or arms of the collar portion of the inner component extend upwardly, ie they are joined at their lower end (by the ring or other structure extending around the circumference of the collar and serving to maintain the arms in their circumferentially spaced apart positions) and their upper ends engage under the lip of the container. This arrangement has many advantages particularly over known arrangements in which a closure, or a component of a closure, has radially moveable parts or arms which extend downwardly and are connected at their upper ends, eg by a top part of the component which extends across and/or closes the mouth of the container.

Another important feature of the arrangements shown in the drawings is the provision of a sealing portion which extends from the collar portion over the lip of the container. Two particular arrangements for achieving this with a collar portion having upwardly extending arms are disclosed. In the first, a flexible sealing portion extends from the collar portion over the lip of the container (and in some cases may also extend across and/or close the mouth of the container). In the second arrangement, connecting parts of the same or similar rigidity as the collar portion (and typically integrally formed therewith) extend from the ring of the collar portion and over the lip of the container. These connecting portions are typically connected together at their upper end by an annular ring and a bore feature may extend from this into the interior of the container. This type of sealing portion preferably carries a flexible sealing member such as an o-ring or compression seal for engaging an upper or inner surface of the container.

If the inner component does not have a bore feature, it is prevented from slipping down the container (when not held by the outer component) either by engagement of the sealing portion with an upper surface of the lip and/or by engagement of the lower end of the collar portion with the exterior of the container, eg if this bulges outwards or has an externally projecting shoulder or rib.

For the avoidance of doubt, the verb “comprise” as used herein has its normal dictionary meaning, ie to denote non-exclusive inclusion. The use of the word “comprise” (or any of its derivatives) does not therefore exclude the possibility of further features being included.

All of the features disclosed in this specification (including the accompanying claims, and drawings) may be combined in any combination (other that combinations where at least some of the features are mutually exclusive).

Each feature disclosed in this specification (including the accompanying claims and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is just an example of a generic series of equivalent or similar features.

The invention is also not restricted to the details of the embodiments described herein. The invention extends to any novel concept, feature, or any novel combination of the features covered by the claims in combination with any one or more features described herein (including the accompanying claims and drawings). 

1. A closure for a container having a circular opening defining an axis and a lip around said opening, the closure comprising: an inner component having a collar portion for locating about the exterior of the container beneath the lip of the container and a sealing portion which, in use, extends from said collar portion over an upper surface of said lip; and an outer component for fitting over the inner component and interacting therewith for releasably securing the collar portion thereof under said lip; wherein the outer component has a skirt part for locating about the collar portion of the inner component, the collar portion comprising a plurality of spaced apart radially moveable parts around its circumference pivotally joined at their lower ends by a structure extending around the entire circumference of the collar portion.
 2. A closure as claimed in claim 1 in which the collar portion is relatively rigid and the sealing portion is relatively flexible.
 3. A closure as claimed in claim 1 in which the sealing portion is relatively rigid and carries a relatively flexible sealing member such that, when the closure is fitted to a container, the sealing member is located in contact with the lip or interior of the container.
 4. A closure as claimed in claim 2 in which the collar portion and the sealing portion are integrally formed with each other.
 5. A closure as claimed in claim 1 in which the outer component has one or more cam features which, when the skirt part of the outer component is fitted over the collar portion of the inner component and moved axially and/or rotationally relative thereto, interact therewith in an axial and/or rotational direction so as to press and/or hold said radially moveable features in engagement with the exterior of the container beneath said lip.
 6. A closure as claimed in claim 1 in which the outer component is releasably secured to the inner component by rotation relative thereto about said axis through 180 degrees or less, and preferably 90 degrees or less.
 7. A closure as claimed in claim 6 in which outer component has a plurality of spaced apart substantially upwardly facing first surfaces around the inner circumference of the skirt part for engaging with substantially downwardly facing second surfaces of said radially moveable parts such that rotation of the outer component through no more than 180 degrees in a tightening direction relative to the inner component and consequent engagement of said first and second surfaces releasably secures the inner and outer components together in the axial direction.
 8. A closure as claimed in claim 7 in which the said first and/or second surfaces are shaped or inclined such that said relative rotation between the first and second components also causes axial movement therebetween.
 9. A closure for a container as claimed in claim 8 in which the outer component has a top part which overlies an upper surface of the container lip and said axial movement moves said top part into engagement with said upper surface, either directly or via said sealing portion.
 10. A closure as claimed in claim 1 in which the sealing portion extends over said upper surface of the container lip and closes said opening.
 11. A closure as claimed in claim 1 having an o-ring seal for providing a seal between the closure and an upper or interior surface of the container.
 12. A closure as claimed in claim 11 in which the o-ring seal comprises a toroid of elastomeric material which is part of or is carried by said sealing portion.
 13. A closure as claimed in claim 12 in which the o-ring is provided on a bore feature which, in use, projects through the opening into the interior of the container, the bore feature being part of the inner and/or the outer component.
 14. A closure as claimed in claim 1 in which the sealing portion does not extend across the mouth of the container so does not close the container opening.
 15. A closure as claimed in claim 14 in which the outer component comprises a bore feature which, in use, projects through the mouth of the container into the interior thereof.
 16. A closure as claimed in claim 15 in which the bore feature comprises a relatively rigid component and an o-ring carried thereby.
 17. A closure as claimed in claim 16 in which the skirt portion of the outer component is able to rotate relative to the bore feature.
 18. A closure as claimed in claim 5 in which said one or more cam features are arranged to press said radially moveable features into tight, frictional engagement with the exterior of the container beneath said lip.
 19. A closure as claimed in claim 1 in which frictional engagement between the inner component and the exterior of the container enables said relative rotation to be effected by a rotational force applied between the outer component and the container.
 20. A closure for a container as claimed in claim 19 in which an inner surface of said radially moveable parts provides a high friction engagement with the exterior of the container.
 21. A closure for a container as claimed in claim 20 in which said radially moveable parts are formed of a relatively rigid material and said high friction engagement is provided by a layer of relatively flexible material forming said inner surface.
 22. A closure for a container as claimed in claim 21 in which said layer of relatively flexible material is part of the sealing portion which, in use, extends over an upper surface of the container lip.
 23. A closure as claimed in claim 5 in which the outer component has a second set of cam features which are arranged to interact with the radially moveable parts so as to drive them radially outwards as the outer component is rotated in a loosening direction.
 24. A closure as claimed in claim 3 in which the inner component comprises a bore feature which, in use, projects through the opening into the interior of the container, the bore feature carrying an o-ring seal which is arranged to seal with an internal surface of the container.
 25. A closure as claimed in claim 3 in which the radially moveable features are biased towards a radially inward position such that they provide a snap-fit with the container as the inner component is fitted over the lip of the container.
 26. A closure as claimed in claim 1 in which the inner component is a snapfit within the outer component as they are assembled axially.
 27. A closure as claimed in claim 1 in which the inner component has a stop feature for engaging a feature of the container for inhibiting or limiting rotation of the inner component relative to the container when the outer component is rotated.
 28. A closure for a container having an opening defining an axis and with an outwardly projecting lip around said opening, the closure comprising an inner member having an expandable/contractable portion for engaging an outer surface of said lip and an outer member for mounting over said inner member such that axial and/or rotational movement of the outer member relative to the inner member, when said inner member is fitted over said lip, is arranged to hold and/or press said expandable/contractable portion into secure engagement with the container beneath said lip, an inner surface of the inner member that contacts the container and/or the outer surface of the container being of a nature such as to provide a high friction engagement between the inner member and the container whereby relative rotation of the inner and outer members can be effected by a rotational force applied between the outer member and the container.
 29. A closure for a container as claimed in claim 1 when fitted to a container to close the container opening.
 30. A container having a circular opening defining an axis and a lip around said opening, the container adapted to receive a closure, the closure comprising: an inner component having a collar portion for locating about the exterior of the container beneath the lip of the container and a sealing portion which, in use, extends from said collar portion over an upper surface of said lip; and an outer component for fitting over the inner component and interacting therewith for releasably securing the collar portion thereof under said lip; wherein the outer component has a skirt part for locating about the collar portion of the inner component, the collar portion comprising a plurality of spaced apart radially moveable parts around its circumference pivotally joined at their lower ends by a structure extending around the entire circumference of the collar portion.
 31. A container as claimed in claim 30, wherein: the inner component has a stop feature for engaging a feature of the container for inhibiting or limiting rotation of the inner component relative to the container when the outer component is rotated; wherein the stop feature is in or on the lip of the container.
 32. A closure as claimed in claim 1 in which the sealing portion is arranged to close said opening with a part thereof in sealing contact with an upper or interior surface of the container, the sealing portion comprising a relatively rigid part which carries a relatively flexible sealing member which forms said part in sealing contact with an upper or interior surface of the container.
 33. A closure as claimed in claim 1 in which the sealing portion is connected to the collar portion by a plurality of spaced apart connecting parts around the circumference thereof which are interleaved with said plurality of radially moveable parts of the collar portion.
 34. A closure as claimed in claim 32 in which the flexible portion comprises an o-ring
 35. A closure as claimed in claim 34 in which the sealing portion is shaped so as to extend into the interior of the container when the inner component is fitted thereto and the o-ring is carried thereby so as to seal against an inner surface of the container.
 36. A closure as claimed in claim 1 in which the inner component can be fitted to the container so as to close and seal said opening prior to the outer component being fitted over the inner component.
 37. A closure as claimed in claim 1 in which the inner and outer components have mutually engageable features whereby the outer component can be secured to the inner component by rotation relative thereto about said axis.
 38. A closure as claimed in claim 37 in which said mutually engageable features form a bayonet thread. 